I had multiple breast infections/plugged ducts with my 3rd, 4th and 5 th
babies 30+ years ago.  Nobody knew anything then but LLL.  I used the
directions from the "blue book" page 102.  Apply heat, get plenty of rest,
and keep the breast empty.  I'd camp out on the couch with a heating pad
and baby (so I could ride herd on the rest of my kids).  I'd favor the sore
side by nursing 1st on that side, sometimes the pain with let down was
excruciating.  I found I had to walk a fine balance between keeping sore
side empty enough and non-sore side from being over full.  (I had a very
abundant supply.)  I frequently had the fever/chills sx.

After the first few I got very blase about using antibiotics and got so I
didn't even call the dr.  Back then antibiotics were a contra indic to BF.
I couldn't see stopping BF to take antibiotics  and I was never able to
hand express well and only had a bicycle horn pump  (do any of you realize
how far we have come?)  I remember one night when I thought - if my milk is
infected and if some of the antibiotic gets in the milk, they will cancel
each other out and went on to BF!  I finally figured out a connection
between abundant supply, bras with elastic around the breast, over tired,
doing too much and my problems slacked off.  My infections(?) seemed to be
connected to overfullness & blockage, bumps to breast could also trigger an
episode - you don't want to hear about the day I raked leaves(boths
breasts, outer aspects),  not sore nipples as a portal of entry.

Other etiologies of sore breasts, plugged ducts - we've all noticed
increased "infections" in the winter months when baby-toddler has URI, the
weekend or day after the baby was christened, or holidays (tired or over
full).  I think we are looking at a whole range of problems and calling
them all breast infections, when they actually aren't one disease or
syndrome.

Sincerely, Pat in SNJ